What's the next two numbers in the sequence below

21, 22, 24, 25, 26,

1, 8, 27, 64,

In the first one I'm going to assume you missed 23 by accident and say the sequence is n+20 so the numbers missing are: 27 and 28.
In the second one, the sequence is n^3 so 5^3 is 125 and 6^3 is 216 so the next two numbers should be 125 and 216.

Hope this helps :)

Given that the height is reduced by 2/5 and the radius is doubled, the new volume will be given by:
V=1/3πr^2h
r=2r
h=2/5h
thus;
V=1/3*π*(2r)^2(2/5h)
=8/15πr^2h
This implies that the new volume will be 8/15 of the original volume